Instead being arguing and insulting, blabbering landowner, you can try to be bit welcoming and learn how to treat people from other countries. Also, you can try not to insult where they are from and explain how bad experience your friend had in your guests country. Maybe your friend was as smug as you are and didn't knew how to talk to people.
Maybe you didn't knew but people who come to stay could be friends, but I guess you never had such chance because of you being you.